Bill Kelso

                                                          IV

                                                   Our Planet

Like our universe and solar system, the earth has undergone many changes over its relatively short life.  The appearance of the earth today is nothing what it was like in the past. It was not until fairly recently that scientists had a clear idea of how much planet had changed in its 4.7 billion years of history. Given the complexity of the topic, we hope to analyze the earth from four different perspectives.

First, we shall see how the earth’s sun, the planet’s shape, position in the solar system, and size affects its behavior today. If any of the above dimensions had been different, there probably would never have been life on earth at all.

Secondly, we will examine the physical makeup of the planet. While our earth was once a molten ball of fire, it has evolved from this hellish like appearance to a planet primarily covered in water to our present world in which 29% of the surface of the earth is land. We will also see that the makeup of the continents has constantly evolved over the planet’s history. Since people naturally want to more about their own country, we shall see how the plate tectonic revolution has affected the makeup of the US.

Thirdly, after explaining how the appearance of the earth has changed, we will see that its climate has dramatically fluctuated over time, swinging from a radically cold earth covered in ice to a radically warm planet experiencing temperatures significantly hotter than today. While today we are worried about global warming, a mere 10,000 years ago the earth finally emerged from an ice age that lasted 2 million years.

Finally, we shall look at the future prospects of the earth. As we learned earlier our universe will eventually disappear as the acceleration of the cosmos may eventually tear every planet and galaxy to pieces. Unfortunately, our planet will also self-destruct in the nearby future. While our universe may last another 14 billion years, the earth will probably self-destruct much sooner in perhaps several billion years.  In speculating about the future, we will see that there are three possible doomsday scenarios for the earth. We will try to predict which of the three options is most likely to occur first. 

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                                      Why our Planet has Survived

a.Why the change in the heat of the sun is cause for concern for life on earth.

In a previous post we talked about how the solar system operates. In this section I want to focus on the unique and dramatically changing relations between our sun and our planet. I also want to show how the variation in the energy of the sun has affected our earth in the past and may seriously compromise its existence in the future.

The reason why this is the case is because the young sun was not always as bright and did not emit as much heat in its beginnings as it does today.

The more feeble and less energetic nature of the earlier sun may explain part why earlier periods of the earth were often colder than today. But the influence of the sun on the earth was tempered by the unusual atmosphere of our earth.  While today there is much talk about the impact of CO2 on our planet’s climate, we have to realize that in its early years, carbon dioxide represented over a third of the earth’s atmosphere while today CO2 is but a trace element in our atmosphere. 

In the early years of our planet the earth often escaped extreme periods of cold because the higher percentage of CO2 in the atmosphere acted as a greenhouse gas and trapped the heat of the sun.

Conversely, when our sun began to heat up and become more energetic, there was the danger that the earth would become overwhelming hot, evaporating away the water in our oceans. However, this scenario never occurred because as the sun heated up, the gashouse gases of CO2 began to decline from 30% of the atmosphere to 20% then 10% until today when it only constitutes four tenths of one percent. Our earth is currently livable because the changes in our atmosphere have offset and mitigated the changes in the solar output of the sun.

However, the future of the planet may not be so bright. The sun is continuing to grow hotter and for the first time in many centuries the amount of CO2 in the atmosphere is likewise increasing. As we shall see at the end of this post, this changing relationship between the sun and out atmosphere is one of three reasons why the future of the planet will eventually come to an end.

b. Why Does the Location of our Planet in the Solar System Matter?

If potential future increases in the temperature of our planet explains why its future may be precarious, our planet’s location in the solar system helps us understanding why it was possible for our planet to initially create life on earth. Today we know that the earth is the third planet from the sun. That location is important because regardless of the changing nature of the sun’s temperature, if the earth were closer to the sun, like Venus, the earth would be so hot that any water on the planet would have evaporated. Conversely if the earth were further out like Jupiter or Neptune, the planet would be so cold that it would also have been impossible for life to evolve. Our present position in the solar system is often called the sweet spot or the habitable zone of a solar system. When astronomers study other solar system, they are always looking for planets like our earth that occupy that sweet spot.

c. Why is the Size of the Earth Important?

Thirdly in addition to our location and interaction with the sun, the size of our earth also matters. If our planet were much bigger the pull of gravity would have been so strong that it would have been impossible for us to walk. The immense gravity would have also made it impossible to form large and expansive mountains ranges like the Rocky Mountains or the Alps.

Conversely if the earth were much smaller, its diminished gravity would have made it much harder to hold on to our atmosphere. But even more importantly if the earth were smaller, the planet would have cooled faster, thus destroying the magnetic field our earth’s molten interior generates, which protects us from the sun’s cosmic ray.

Whenever an electric current is moving it creates a magnetic field. Inside our earth’s hot interior, the movement of molten lava creates such a current which today shields our earth from harmful solar rays. We can see the efforts of that magnetic field in northern areas like Alaska or Norway in what today is called the northern lights. As our magnetic field funnels charged particles from the solar wind towards the Earth’s poles, they coincide with gases in the upper atmosphere creating the light show called the norther nights or more commonly Aurora Borealis.

If the above magnetic field had not blocked the cosmic rays or wind from the sun, the sun would eventually have blown away our atmosphere making it impossible for life to form on our planet.  

The latter case may be the situation with Mars which is only half of our size. At one time it may have had an atmosphere but as the planet cooled fairly quickly because of its small size, it lost its magnetic shield and then its atmosphere.

d. Why is there Water on the Earth?

When our solar system was created there were four interior rocky planets (including Earth) that are generally dry and four outer planets that are primarily made up of gas and ice. Because of this division in our solar system, astronomers have always wondered where the earth got its large amount of water that created our oceans. One very dominant opinion is that comets and meteorites from the outer plants are responsible for the creation of our many oceans. If it were not for this interaction between the interior drier and the wetter outer planets our planet would not be like the earth we know today.

e.Why is our Planet Round?

A final issue about our planet that elicits comment is the ever present question as to why the earth is round. Ever since we have attended grammar school, we are taught that that the earth is round. But that leaves unanswered the question why that is the case. The answer is our old friend gravity. Our planet as well as all other planets and our sun are all round because gravity will transform any cloud of dust into a round sphere. 

This observation only reinforces the amazing significance of Newton’s theory that gravity rules the universe. While an apple falling to the ground, the presence of high tides in our oceans, the revolution of the earth around the sun, avalanches on the side of a hill as well as the apparent round nature of our planet all seem to be totally unrelated events, Newton was able to realize that each of these apparent disparate events actually had the same cause. 

Whereas before Newton, people had no idea how the universe and its complex interactions worked, Newton showed that a simple law explained many events in our world. Newton’s discovery thus proved that there was some coherence and logic to the way our world operated.

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                                    The Changing Appearance of the Earth

In the above section we analyzed how the size, makeup and location of the planet enabled our earth to create complex life forms. In this second section we want instead to provide more of a descriptive picture of how the earth has changed over time. After we describe how the physical appearance of the earth has historically evolved, we will see how its climate has also varied in the course of its relatively short life.

a.A Brief History of the Earth's Geology

To appreciate how the makeup of the earth has fundamentally changed over time, we could argue that the earth has altered its appearance three time.

1.Dante’s Inferno

When the earth first appeared it was a molten ball of fire in which massive volcanoes spewed out toxic chemicals.  During this time the earth was also being bombarded by many meteorites which contributed to the hellish nature of the early earth. In the middle ages there was a famous book called Dante’s inferno and that title was descriptive of our early earth.

2.A Watery World

In the second phase the internal molten nature of the earth began to cool, stabilizing the outer surface of the planet.  While the internal makeup of the earth became less volatile, the earth also witnessed a barrage of comets who began to transform the earth into a watery planet. By around 2 million years ago, our planet was essential a sea world as around 90% to 95% of the planet was covered in water. There were no continents like Eurasia for terrestrial plants to occupy.

3.The Growth of Continents

Fortunately, the watery world was merely a passing phase in the history of the earth. In its third phase the earth began to resemble the earth we know today around 2.7 billion years ago.  With time the molten interior of our earth began to produce a new kind of rock formation called granite that was buoyant which quickly began to float to the surface of the ocean creating the land masses that we today call continents. Over the next several billion years the earth acquires its present appearance in which 29% of the earth surface is made up of land and 71% consists of water. 

But this land is nothing like the land we see today. The continents were large dusty plains lacking in any kind of green plants and animal life. It was not until 460 million years ago that plants began to colonize our continents developing the forest and grassland that characterize the planet today.

b. The Idea of Moving Continents

While geologists finally began to study our planet, they initially through that the earth’s five continents had always existed in their present form. Unfortunately, it took them several centuries to finally appreciate how the makeup of the continents had also been transformed over time.  Not until the middle 1960s when the Plate Tectonics Revolution occurred in geology, were geologists aware that our continents floated on a variety of movable raft like plates that were constantly moving. Because the interior of the earth has a molten out core, it generates heat within the earth’s interior which created convection currents in the mantle causing the tectonic plates to shift and slide about. 

In some cases, the earth’s convection currents may cause the various continents to crash into one another creating one gigantic continent.  That was the case during the early Age of the Dinosaurs when they lived on a massive continent called Pangaea. But as they did more research, geologists found that the earth has had perhaps two and even possibly three massive continents like Pangea 

At other times the earth’s interior heat may break up rather than consolidate continents. That has been the situation for the last 200 million years as a variety of rift valleys split Pangea into the present five continents that currently make up our world. 

c. New insights in Geology

The plate tectonics revolution had an immense impact on the field of geology. Prior to this revolution in the 1960s geologists never had a satisfactory explanation as to why mountains existed or why they were only found in certain parts of a continent. When they realized that continents often crashed into one another or were broking up by rift valley, they finally had a theory to explain the geological world around them. 

d. The Impact of Plate Tectonics on the Makeup of America

While the study of our changing planets is a fascinating topic, perhaps because of our limited time, we should finish by showing how the plate tectonics revolution even changed our understanding of our own country.

Like Africa America has had significant rift valleys caused by the interior heat of the earth remaking our national geography. Before those rift valleys occurred, America crashed into Europe helping to create the super continent of Pangea. One consequence of the collision was the creation of the Appalachia Mountain chain over 300 million years ago. When that super continent subsequently began to break up around 180 million years ago, a rift valley split America from Europe. The mountains of eastern Norway, Eastern Scotland and Appalachia were all created by the collision and then the separation of the continents during this period of geological activity. 

Besides the above major rift valley there was another smaller and less successful rift valley in America that initially tried to split the American continent in half. When it stalled out it created a depression in the middle of the continent that led to the development of our Mississippi River.

e. How our Continent and Country will eventually Disappear

Although our continent of North America appeared 180 million years ago, geologists calculate that in another 250 million years it will disappear as it collides with China. Because California moves about one inch closer to Asia each year, it will eventually become part of the large Eurasian continent . Just as there once was a gigantic continent Pangea that split into five separate continents, in the future the five separate continents may be reassembled into yet another super continent.

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                                    The Changing Climate of the Earth

Today there is much talk about climate change. In this third section of this post, we hope to show that the climate of the earth has never been overly stable or constant in nature. At its birth the earth was a molten ball of fire. 

a.A World of Heat. 

At the same time there have been other periods in our planet’s history where the earth created hothouse like conditions through a super greenhouse effect. While today we are worried about the growth of CO2 in the atmosphere, the earth’s atmosphere presently has only trace amount of carbon dioxide at .04 while 78% of the air is nitrogen and 21%. of the atmosphere is oxygen.  

However, as explained previously, for most of the earth’s existence CO2 has been around a third of the world’s atmosphere and it has only declined significantly over the last 200 million years.  Even in the age of the dinosaurs, carbon dioxide levels were close to five to 10 time higher than we are currently experiencing. In the Jurassic period temperatures were anywhere from 15 to 18 degrees hotter than today and no part of the earth was covered by ice. 

b. A World of Ice. 

While the earth has had numerous period of extremely warm temperatures, twice in our planet’s history the earth was a snowball earth completely covered in ice and devoid of life. In addition to these extreme periods of cold, the earth has suffered from 5 other ice ages in which part of the earth was covered with snow, the last period ending only 10,000 years ago. The Great Lakes were created when the snow covering the middle of America finally melted while Long Island, off the coast of New York City, was debris left over from the advancing glaciers on the east coast. 

We thus have to realize how unique our present climate is. Historically the earth has fluctuated between very cold and very hot and human climates. After all, only 10,000 years ago the world was in the midst of an ice age that covered all of Europe, Canada as well as New York City and the upper middle west. Based on the past history of our globe, it is probably the case that the benign climate of the last several thousand years will not last indefinitely. 

c.The many factors that shape the Earth’s Climate

There are many factors that can alter the earth’s climate most of which are beyond human control. Below is a list of five natural events as well as a human event that can affect our climate. 

1.How Hot and Energetic is the Sun

As the Sun becomes both brighter and hotter over time it can dramatically heat up the earth. Its success in achieving that goal, however, also depends on how many greenhouse gases exist in the atmosphere of the earth. If the sun becomes hotter but the percentage of CO2 in the air declines, the climate might remain relatively constant. But in the future, it appears that both the temperature of the sun is likely to increase and the percentage of carbon dioxide in the atmosphere is bound to grow.

2.The Orbit of our Planet

a.The Orbit of the earth may vary by becoming either more elliptical or circular in nature? If the earth’s orbit becomes more circular the planet’s climate will become warmer, but if it becomes  more elliptical it would become cooler.

b. The Tilt of the Earth. If the earth become more tilted, our planet would experience much hotter summers.  

c. The Wobble of the Earth on its Axis. Finally if the Earth likewise increase its wobble on its axis (called axle precession) it would also increases its temperature during the summer season.

3.The Activity of Plate Tectonics

Similarly the activity of Plate Tectonics and the resulting volcanic activity can affect how much carbon dioxide is in the atmosphere. In most volcanic eruptions 35% of the discharge is carbon dioxide and 13% sulfur, another greenhouse gas.

4.Volcanic Activity & the Atmosphere

If volcanic activity increases the production of greenhouse gases, it may also release enough volcanic ash into the atmosphere that it may block sunlight hitting the earth temporarily cooling the planet. Volcanic activity can thus both enhance as well as mitigate global warming.

5.The Location of our Continents and Ocean Currents

If the location of our continents changes it may alter wind and ocean currents prompting climate change.

6.Human Activity

Finally as the news media constantly reminds us human activity in burning fossils fuels can likewise alter the climate.

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                          The Future of the Earth: Three Doomsday Scenarios

Astronomers think our solar system, like our galaxy is in middle age and the sun and solar system will die out in several billion more years. In the final section of this post we need to ask why the planet’s future is so endangered.

As of today there are three main theories as to why our planet will self-destruct way before the universe dies out. 

The first theory which will probably be the last reason the planet dies, argues that the planet will be totally incinerated when our sun finally runs out of fuel and explodes. As the sun runs out of fuel it contracts and then ignites a shell of hydrogen around the core pushing the outer layers of the star outward that will eventually consume the earth. This option may occur within 5 billion years from the present.

The second theory of the earth’s demise focuses on the growing heat of the sun as it ages. As the sun warms up, it will eventually also heat up the air and perhaps boil away our oceans and turn all water supplies on earth into water vapor. This option will probably occur several billion years before the sun collapses.

The third and final theory argues that earth will die because our planet will eventually cool and the molten interior of the earth will cease to exist. As the molten interior declines, the earth will lose its magnetic shield which prevents solar winds from destroying our atmosphere. This last theory will probably be the earliest reason why out planet will eventually experience the same fate as our neighbor Mars.

In light of these three options, it is also easy to understand why so many astronomers today are trying to find other planets and suns that can sustain complex forms of life. The hope is that before our solar system and planet eventual dies, that we will be able to send colonies to another planet. While that option will eventually also expire once the universe comes to its end, it will at least enable humans to live another day. 

Bill Kelso

                                                  A Postscript

                                        Why the Sun is Getting Hotter

After the last post I was asked why the sun is getting hotter. I originally left that material out of the last commentary as the post was getting too long. Also I thought if people were going to read these commentaries they probably wanted at best a quick overview rather than something that was too technical in nature. However, in case you are interested in this subject, the topic is an fascinating study of how the natural sciences have come to better understand our world. What is interesting about the question our classmate asked is that until about 120 years ago, nobody in the world had any idea why the earth’s sun was becoming much warmer.

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                          The Nature of Matter

The first breakthrough occurred because of another insight by the man who dominated 20^th century physics Albert Einsten. Prior to the turn of the 20^th century, people thought energy and matter were two very different substances. However in 1905 Einstein argued that matter and energy were the same thing, that  they were merely two states of the same substance. This concept which today is known as mass energy equivalence essentiallymeans that mass and energy are interchangeable forms of the same thiing.

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                                          How Much Energy is in Matter

Not content with the novelty of this insight, Einstein went one step further and calculated how much energy is in any piece of material. He achieved this in the following very famous equation:  

                                                              E = MC2

He argued that the amount of energy in any object could be found by multiplying its mass by the speed of light squared. The significance of this equation is startling. If you happened to walk in your backyard and found a small rock you might think it had little energy in it. But as soon as you realize that the speed of light is 186,000 miles per second, and that number when squared is 34,596,000,000 miles per second, you quickly realize even the smallest rock possess a tremendous amount of energy.

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                                     How does the Universe create Energy

Once scientists realized how much energy is contained in the mass of objects, they began to wonder how the various suns in the universe generated the energy to light up their solar systems, They initially thought there were two answers.

a.Fission

First they hypothesized that our  sun could be splitting complex atoms in half to generate energy, a process known as fission.

b. Fusion

However a second option they entertained suggested the various solar bodies might be combining atoms, rather than splitting them  apart to generate sun light, a process known as fusion.

Since the early universe was primarily made up of simple atoms like Hydrogen and some Helium, astronomers deduced that the sun was generating its energy primarily through fusion, or the process of combing different elements together. 

When they looked up at the sky during a bright day scientists were estimating that that number of hydrogen explosions was immense. During an average day of sunlight the sun was experiencing over 100 million hydrogens bombs exploding simultaneously. 

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                            Why is our Sun getting Hotter as it gets Older?

In  light of the above findings, we can now understand why the sun is getting hotter. When our sun was first formed it was primarily made up of hydrogen atoms. But once nuclear fusion began, the sun started to fuse together simple hydrogen atoms resulting in the release of a tremendous amount of energy. But when it fused two hydrogen atoms together it created the much heavier chemical elements like helium or oxygen. As these heavier elements proliferated, they began to sink into the core of the sun making it much more dense and significantly hotter. The longer the fusion process goes on, the denser and hotter the sun becomes which eventually affects the amount of sunlight that hits the earth.

While our sun when it was first created was rather dim and nowhere as hot as is presently the case, it has become significantly hotter with the passage of time. Fortunately the decline of CO2 has mitigated the increase in the overall temperature of the sun. But sometime in the distant future, the temperature of the sun will increase to such an extent that it probably will jeopardize any life forms on earth.

Bill Kelso

                                                           V

                    The Growth of Life in Our Corner of the Universe

The development of life on earth  has always been a controversial topic.  A perennial issue is the question of whether life on earth is a unique and rare event or whether life is widespread in both our galaxy and universe. 

a.The Abundant Life versus the Rare Earth Hypothesis

As astronomers discovered that the universe was full of galaxies rather than just solitary stars, they surmised that there must be billions of other solar systems that could and probably did support life. For them life was a common and abundant feature of our universe.

However, the opposing view, which is called the Rare Earth Hypothesis, argues that the odds of creating advanced or intelligent forms of life are so rare, that we human on earth may be the only advanced form of life in the cosmos. If you recall our previous post about earth, you will recall that only certain types of fairly rare planets can sustain life.

For instance, a planet would have to be in that sweet spot of being close but not too near its sun. It would also be desirable if the planet were of medium size and neither too small nor too large. If it were too small, it might be unable to retain its atmosphere while if it were too big the planet’s strong gravitation pull would prevent animal life from moving at all. Likewise, a planet might need to have a moon to prevent it from spinning to fast if it wants to have a normal period of daylight.

b.The Darwinian versus the Punctuated theory of Evolution

The above dispute between the Rare Earth and the Abundant Life school reflects the earlier discussion we had about the Punctuated Theory of Evolution. While most biologists thought up until the 1960s that life was generally stable on earth and only incrementally changed over time, its opponents argued that life was more volatile and unpredictable in nature. 

But equally important, the advocates of Punctuated Equilibrium also insisted that evolution was often driven by a range of factors such as the impact of a meteorite that traditional biologists had ignored. 

In this post and the following one about the evolution of modern humans, we will see that the traditional view of evolution taught in high school about the impact of natural selection on genetic mutations is only part of the story. In its place we will see that plate tectonics and rift valleys as well as comets and meteorites may be equally important in the creation and design of life. 

This point is important because if the creation of intelligent forms of life were caused by a wide array of factors ranging from geological disturbances to cosmic events, it lowers the odds that other planets might reproduce the kind of life forms found on earth. That is especially the case if the origin of human life on earth seems contingent and even accidental in nature.

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                                              Origins of Life on Earth

                                                    The First Phase

To develop this argument further we need to look first at the creation of life on earth. Before life could appear on earth, it had to go through 3 distinct phases before it was capable of supporting complex examples of life.  In the earth’s 4.7 billion years of existence the first phase lasted about a billion years. Surprisingly enough, this phase which actually did not see the creation of any life at all, was most remarkable for its development of an environment that could support and sustain diverse life forms. 

a.The Evolution of a Sterile Environment

To appreciate the above argument, we have to realize that the initial universe possessed a basically sterile environment because of its simple chemical makeup.  When the universe was first created in the big bang, it consisted of just the two elements hydrogen and helium. Because there were no complex chemicals like carbon or oxygen in the early universe, it was impossible for any kind of sophisticated or complex forms of life to evolve.

However, after the passage of time, when the hydrogen and helium formed stars in the early universe eventually exploded, the situation changed dramatically. As primitive stars of the early universe ran out of fuel, the heat of their subsequent supernova blasts created new minerals such as silicon, carbon or iron which eventually could sustain life forms like plants or animals. We have to remember that the chemical elements found in the periodic table that people study in high school chemistry classes today, simply did not exist until the early primitive stars of hydrogen and helium blew up, creating a whole new array of chemicals.

These newly created chemical elements which were dispersed into outer space eventually formed giant gas clouds. While it is unclear as to what events actually caused the resulting gas cloud to congeal, it is possible a nearby star exploded, condensing the above gas cloud into our modern solar system

b. The Creation of a Longer Day

Secondly, as we learned earlier, even when our solar system possessed its enriched set of chemicals, our earth was spinning so fast, that the average day only lasted 10 hours. At that rate of rotation, there is no way the early earth could have supported any complex form of life. Any major forms of animal or plant life would have lacked an environment that would have provided them with the time to obtain food and to rest at night.

However once the planet Theia smashed into the earth and created our moon, its gravitational impact on the earth eventually slowed down the rotation of the earth, creating our much longer and life sustaining days. During this first phase, our universe as well as our planet which had initially been hostile to creating any form of life now possessed the chemical building blocks necessary to build as well to sustain life.

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                                                    The Origins of Life

                                                     The Second Phase

But even with the above advantages, when our planet was finally able to support life around 3.7 billion years ago, the appearance of life forms on earth was rather a prosaic and non-spectacular event. After being sterile for a billion years the earth finally acquired very simple microscope forms of life called microbes. But over roughly the next 3.2 billion years, those microscopic forms of life barely evolved.

This extended period of time raises the interesting question of why or where did life finally emerge on our planet. There are two main contending theories. 

a.Volcanic vents creating Rift Valleys

The first theory argued that life arose in the volcanic vents that caused rifts in our world’s continents. Allegedly the heat that causes the transformation of our geology also generated new forms of microorganism that were a primitive form of life. 

b. Microbes from outer Space

However, a second theory argues that these early microorganic forms of life including simple bacteria may have originated in space. This theory which is called panspermia has several different versions. The most intriguing one suggest that the earliest forms of life may first have appeared on Mars and then subsequently migrated to earth. Due to the activity of a meteorite, Mars may have helped life to colonize earth. 

Regardless of which theory we subscribe to this second explanation suggest that very primitive versions of life may be widespread in the universe as a whole. Perhaps it may suggest that the theory that life is widespread in the universe may even be true. 

While the story about the origins of life is intriguing, the aftermath of that event is rather boring and uneventful. As noted above, once these simple forms of life appeared on earth, nothing much happened for the next 3.2 billion or so years. 

It was not until roughly 550 millions years ago that more complex forms of life such as plants, or amphibians or reptiles finally appeared on earth. For the longest time the earth was a dusty planet covered only by dirt and totally barren on any form of life. As the theory Punctuated Equilibrium argues there are often prolong periods of stasis followed by dramatic periods of creation or destruction during evolution.

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                   Why did it Take so Long for Life to Evolve in our Universe       

                                                   The Third Phase

After a prolonged period of stagnation, the scenario predicted by Punctuated Equilibrium finally occurred. In the third and final phase life exploded on the planet beginning a roller coaster ride in which periods of rapid growth of new complex forms of life like fish, mollusks reptiles or mammals were then followed by periods of mass extinction, which in turn were followed by yet renewed periods of life. 

This first and initial burst of life, which today is known as the Cambrian Explosion, occurred roughly 540 million years ago. 

If you judge this period of dramatic creation and mass extinction by the notion of human history, it may seem like a long drawn-out period. But if you judge this alternating pattern of mass creation followed by mass extinctions and rebirth in light of the earth’s history, it all occurred in the blink of an eye. In the 4.7 billion years of our planet’s existence, only in roughly the last 500 million years have significantly life forms existed. 

a.How Oxygen created Complex Life Forms

That example naturally raises the question as to why it happened.The simple answer is the growth of oxygen. While the earth could sustain simple forms of life with its advanced chemical makeup and lengthening days, it could not develop more complex examples of animals or plants without the presence of oxygen. 

Why is that the case? When animals consume fuel they need some method to extract energy from that fuel. With the presence of oxygen animals can engage in a process we call respiration that enables them to conduct a controlled chemical burn of their food or fuel. In an anaerobic environment or one without oxygen animals cannot obtain enough energy to live a complex and active lifestyle.

Even though the simple microorganism could generate small amounts of oxygen, it took a while before there was enough oxygen to support large complex forms of life such as plants or animals. Fortunately, with time blue green algae developed photosynthesis which converted CO2 into glucose which fostered the growth of green plants and later the numerous animals forms found on the planet today.

b. The Fluctuating Levels of Oxygen on Earth

While the growth of oxygen explains why major forms of life finally appeared on earth, the development of oxygen often fluctuated widely. Initially once complex life forms evolved on earth, the planet’s atmosphere contained only around 10% oxygen as opposed to the 21% it presently registers. But over time the numbers have been as low as 6% and as high as 35%

c.How Life Came to Colonize Land

Because the initial levels were so low, animal and plant life could only exist in the oceans which shielded them from the dangerous rays of the sun. While there was a dramatically growth of complex life forms around 540 million years, those enhanced life forms were not able to colonize land until roughly 55 to 60 million years later. Why was that? Until oxygen levels dramatically increased to create an ozone level over the earth, life forms were subject to harmful solar radiation if they ventured on to land. Prior to this phase, the waters of the oceans had protect animal life from the dangers of intense sunlight.  But once the ozone level had grown sufficiently to the point where it could effectively block out harmful ultraviolet radiation, animal and plant life could safely colonize the earth’s continents.

d.The Challenge Facing life in a Low Oxygen World

While the growth of the ozone level was a necessary change, it was not sufficient to facilitate animals successfully colonizing the land.  Even when microscope life was sufficient to create the ozone shield the levels of oxygen were still lower than what we find today. As mentioned above, today 78% of the atmosphere is nitrogen and 21% is oxygen. But if we return to the earth 550 million years ago, the level of oxygen was a more inadequate 10%. 

e. The Growth of Air Pumps or Lungs

Unless an animal was extremely small it would have had a hard time acquiring enough oxygen to sustain itself on land at this level of oxygen. The final piece of puzzle that that was necessary for our ancestors to colonize land was evolution of an effective set of lungs to breath. In water most fish use a passive set of gills to extract oxygen from the oceans. But once animals tried to venture onto land, they needed to have a more effective set of lungs to replace gills if they wished to effectively metabolize their foods.

For our mammals in general and our human ancestors in particular the development of the diaphragm which is in effect a human pump for acquiring the necessary oxygen achieved that goal. The diaphragm is a large muscle at the base of our lungs that enables us to breathe by the muscle contracting and flattening when we inhale, which creates space in the chest cavity for the lungs to expand and pull in air. 

If you are unclear about this procedures, try breathing while you are reading this post and you can feel your diagram moving up and down. While today we have man-made pumps, mother nature made human pumps millions of years earlier which enable our distant ancestor to successfully colonize land.

Finally our diaphragm is not only a human pump that helps us inhale and exhale, but it is also a pump that can increase abdominal pressure which assists us in passing urine and stool. The diaphragm is thus a dual purpose pump that enabled all mammals to adjust and survive in an earlier environment that was much harsher than our present environment.

Unfortunately, today people may not appreciate the significance of this simple change in our anatomy. When the atmosphere’s level of oxygen was around 15% or lower many millions of years ago, most animals were probably incredibly sluggish and their life was a struggle. The growth of an air pump thus helped us to survive when oxygen levels were incredibly thin. 

f. How Air Pumps Affected McClatchy’s Football Team

Ironically enough, an evolutionary development that led our ancestors to survive a period of low oxygen, eventually enabled humans to live an incredible vigorous and active life when oxygen levels rose to 21%. If you ever attended a McClatchy football game in the 1960s you have to realize that the fancy and energetic running of backs like John Anderson, Tommy Relles, Mike Nishio and Tom Tash would never have been possible without our air pumps.

You also have to realize that if the level of oxygen which only reached 21% around 30 million years ago declines significantly in the future, our urban civilization would dramatically change for the worse. Even with an air pump, if oxygen levels hit 15% it would be impossible for anyone to engage in a myriad array of activities, we take for granted such as playing sports, traveling to distant countries, working long hours at the office or staying out late at night on a date. The situation would be comparable to the whole world suffering from COPD, wearing oxygen masks while living at a rest home for the elderly. With those levels of oxygen, the ability of people to enjoy a productive society living a normal active life and consuming household and consumer good would also be severely compromised.

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                                      The Final Piece of the Puzzle

                                   Further Evolutionary Developments

a.Origins of Mammals                 

While the above discussion explains the early development of life on earth, we don’t have time to examine all the steps that finally lead to our species. To save time we now need to skip over many millions of years to focus on developments that led to human evolution.  Of all the animals created in the last 500 million years, that one that is most relevant for our purposes is the development of the mammals. These were the first animals that were warm blooded and produced milk for their off springs, who are our first major ancestors, and they appeared around 220 million years ago. But while mammals appeared relatively early in the history of the planet, they were mainly small rodent like animals who tried to stay out of the way of the large dinosaurs that then dominated the world.

b.When did our Mammals Ancestors Dominate the World

However, around 66 millions years ago an asteroid hit the earth killing of the dinosaurs which enabled the then small mammals to take over the world eventually leading millions of years later to the rise of modern homo sapiens.

c.Why Did Out Early Ancestors Decide to Live in Trees

Why did our earliest mammal ancestors, who were like small rodents, eventually decided to live in the canopy of the rain forest?  The main reasons is that they hoped to avoid land based predators who were rapidly filling the empty niches in land that resulted from the death of dinosaurs. Since most land predators were four legged, they could not attack our early ancestors who were high up in the trees.

In the forest canopy our mammalian ancestors quickly evolved into three different species.  The first species to develop were the monkeys who walked on all four of their hands and feet on the top of tree branches Secondly were the chimps who swung underneath the tree branches (a process called brachiation) and thirdly were the early Homo Sapiens who were unique in that they walked upright on just their two legs on the top of the forest canopy. 

When monkeys became heavier one set of monkeys the baboons began to forage on land while relatives of chimpanzees who likewise became much heavier retreated to the ground and today are called great apes. Finally when our ancestors were forced to climb down from the trees as the rain forest was dying out, and started to permanently live on the ground like the baboons and great apes, they became known as Ardipithecus. 

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                                      Why the Future is Problematic

While the study of our mammalian and primate ancestors is naturally of interest to us it should not distract us from the larger question of what is the future of life on our planet?

The rather checkered and variable history of our planet raises troubling questions about what lies ahead. In the 500 million years since the Cambrian explosion the earth has experienced 15 periods of massive die offs, including 5 main extinctions in which 75% to 90% of all species on earth were wiped out.

a.Why Massive Die Offs Occur

At the present time, there is intense debate as to why there have been so many periods in which so many species died. Currently most people think there are a variety of reasons. The include meteorites that may have attacked the earth, destroying in the process most of the vegetation on earth. Yet others have suggested that the volcanoes created by continents crashing into one another by plate tectonics may have created such a toxic atmosphere that it led to a massive die off. Finally many analysts think the fluctuating nature of oxygen in the air may also be responsible for the demise of many life forms as animal and plants suffocated to death.

Regardless of its causes mass extinction of so many plants and animals, as well as the fluctuating levels of oxygen in our atmosphere suggests that the future of the planet may be problematic.

As we mentioned at the beginning of this post a week ago, for the longest time natural and social scientists believed otherwise as they insisted that the world was generally stable and that any change on  earth was most likely to be incremental in nature. Given our rather short time perspective as humans, it is easy to understand why scientists assumed that the future would be as the same as in the  past. Today we know that optimistic scenario may not be warranted. In light of the above changes on our planet we have to realize that even if humans and other forms of life survive, they may face difficult and challenging times many centuries into the future. In the 10,000 years since the last ice age ended we have built a major civilization. But it is an interesting question what our civiliztion will look like in another 10,000 years.

b. The Good Fortunes of our Generation

Our generation should be thankful that we just happened to live on our planet in a period of relative stability in which neither the climate, oxygen levels or die offs have significantly affected our lives. As we face the prospects that our time on earth is limited, we should be thankful we lived in a relatively stable and enjoyable period in the history of the earth.

Roger Kircher

I'm enjoying your posts Bill, keep'em coming please.

Bill Kelso

Thanks Roger

Bill

Diane Hinesley (Malone)

Bill Kelso

Diane

Wow? I am really impressed with your travel schedule as you have been to Nepal in Asia, Peru in Latin America and you finished up in the Caribbean with St. Lucie. I also think you deserve a lot of credit for volunteering to help young kids in all of those countries. That is very kind of you and it is a positive reflection on you for all of your concern for other people.

But equally important Diane is your sense of adventure. You have certainly lived an exciting and thoughtful life and been to places most of us have only read about. Thanks for letting us learn about all of your experiences traveling the world..

Bill

Bill Kelso

                                                         VI

                                The Growth of Human Life on Earth

As we stated at the outset of this post a week or two ago, prior to the late 1960s paleontologists and physical anthropologists had little knowledge of where, when and how humans first appeared on the planet.  But after years of major archaeological work in Africa, and important discoveries of fossils like the famous skeleton of Lucy in 1974, and equally important fossil of Ardi in 1994 paleontologists and physical anthropologists now have developed a rather good picture of the origins of early man. That home lies in Eastern Africa.

a.The Rain Forest and The Original Eden

The original Eden where man first emerged may be found in the broad plains that today make up the savannah of eastern Africa. Surprisingly enough, a major shift in the earth's geology may be responsible for the development of modern humans. We now know that around 5 to 6 million years ago, the growing Rift Valley in Africa had created a large mountain chain which blocked rainfall in eastern Africa. Land which had once been a tropical jungle, now began to dry up and become transformed into a semi dry savannah.

                                     The Rain Forest which dried up in East Africa

(If you hit the link below it shows the Awash Valley where the famous Lucy and Ardi fossils of early man have been found. It is possible  that the Awash valley is our original Eden or one of the earliest sites where our ancestors first emerged)

                                          Origins of Man: The Awash Valley

b. The Savannah of East Africa

The rise of the Rift valley which dramatically changed the vegetation in eastern Africa eventually led to the creation of our earliest ancestors. Our former relatives who lived in the tropical forest of Africa, witnessed their environment changing before their eyes, forcing them out of the trees and onto the flat savannah of eastern Africa.  Geographical changes in the earth thus played a major role in creating us, modern day humans, who eventually became a new species on earth about 250,000 years ago.

                                        Pictures of the Savannah of East Africa

Instead of humans living and sleeping in the canopy of a rain forest, primarily living off of the fruit from their tropical habitat, they now had to learn to survive living on the dry savannah. In place of the safety and abundant food supply of the forest, they now had to deal with predators as well as invent a new diet as the lack of rainfall limited their former food supply. In place of being fiber and fruit eaters, humans had to become omnivores who primarily relied on gathering tubers, scavenging or hunting to feed themselves in a semi dry climate.

Fortunately for early man. the geographical changes which forced men out of the homes in the rain forest, also opened up new ecological niches for animal life. Whenever there are unoccupied niches in nature, evolution quickly fills those slots. Today that change is reflected in the large herds of zebra and wildebeests that occupy the plains of east Africa. Once the rain forest thinned out, zebra began to appear about 4 million years ago followed by wildebeest 2 million years later. The roughly parallel development of our ancestors and the large herds that to this day still occupy the savannah of east Africa, guaranteed an adequate source of food for our early ancestors.

In the span of roughly 5 to 6 million years, we early humans were transformed from being basically another primate who lived in the canopy of a topical forest into a kind of proto human who was forced to quickly evolve on a semi desert savannah surrounded by dangerous predators.  

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                                      The Four Stages of Human Evolution

1)Ape Man or Ardipithecus. The Famous Ardi of Ethiopia

The Evolution of modern man went through four stages. In the first state which lasted from about 5 million until 4 million years ago, our ancestors were best called ape men or proto humans. Physical anthropologists technically call this early version of mankind Ardipithecus. It is named after a famous human fossil which has been called Ardi, one of our earliest ancestors which was also found in the Awash valley. While this early human is related to apes and chimpanzees, it is still an open question as to whether our earliest ancestors actually evolved from them. An alternative possibility is that humans, include our Ardi, as well as the other primates including chimpanzees may have evolved from a common ancestor.

                                                   A Reconstruction of Ardi

2)Australopithecus. The Famous Lucy of Ethiopia

As momentous as this first major development was, around 3 million years ago, our early ancestors went through yet another major change. In technical terms, physical anthropologists call this new evolved species of a proto human an Australopithecus and the most famous member of this new species is the famous skeleton called Lucy, presently also found in the National Museum in Ethiopia.

                                         A Reconstruction of what Lucy looked Like

3) Early Humans: From Homo Habilis to Neanderthal 

Thirdly after roughly 2 million years of natural selection, our proto human ancestors called Australopithecus and their famous representative Lucy were transformed into a version of early man which we can call humans. But in evolutionary terms we still had a ways to go before this early version of a human began to resemble a modern man.  Paleontologists have found that roughly 8 previous versions or species of this early human existed before they finally evolved into ourselves, modern day Homo Sapiens. Among our previous predecessors were species called Homo Habilis, as well as our more famous modern cousins Homo Heidelbergenesis who are more commonly called Neanderthals. For thousands of years modern humans shared the planet with these other species until eventually they all died out around 50,000 years ago. 

                                            A Reconstruction of Neanderthal

4) Finally The Rise of Modern Humans or Homo Sapiens

Finally in the fourth and last stage of human evolution, all of the above previous forms of early man were eventually replaced by the development of modern humans whom we call Homo Sapiens. This final version emerged around 250,000 to 200,000 years ago in Eastern Africa.         

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                              Early Evolutionary Adaptations of Mankind

As mentioned in a series of earlier posts, we described how proto humans quickly evolved once they had to make life on the savannah. Many of our anatomical features which were suitable for living in the canopy of a rain forest were ill suited for living full time on the semi-arid plains of west Africa. 

a.Changes in our Feet and Legs

When we made our living traveling in the treetops, our feet had a disposable big toe that resembled our disposable big thumb today. Because such a foot made it hard to walk let along run on the savannah plain the big toe eventually straightened out and became rigid and aligned with all of our other toes.

While living in the forest canopy, our arms were also much longer than our legs. If you spend all of your time climbing trees you main source of propulsion will naturally be your arms. For that reason early man, or Ardi, had arms that were much longer than his legs. But once we humans started living full time on the African plains, evolution altered our bodies so that today our legs are significantly longer than our arms.

b.Changes in our Facial Features

Besides altering the structure of our bodies evolution altered our facial features. In the rain forests of Africa chimps as well as primate humans had protruding jaws because they had higher grinding power that was necessary for them to digest or crack open fibrous and raw food materials. When initially early man began to walk on the savannah he also  had to eat tough fibers which resulted in our ancestors having a large set of incisors, canines molars and premolar teeth. 

When humans finally began to hunt and altered their diet by becoming meat eaters which they subsequently learned to cook, they had a much easier time consuming their meals. The thus did not need a lot of grinding power to eat meat that had been soften due to cooking. As their diet changed so did their teeth which consequently also altered their facial features. 

As their teeth became smaller, their faces became much flatter. Once their faces became more vertical, their noses which had been embedded in their face, became enlarged and now came to dominate their overall appearance. If you look at the following two links, you will see how in a fairly short time, humans acquired a very different appearance.

                                     A Reconstruction of what Lucy looked Like  

                                     Side view of Humans with a Definite Nose Profile                   

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                            When Did Human Leave Africa for Europe & Asia

After living in Africa for 140,000 to 190,000 years, some humans began to leave their initial home for the northern part of the globe around 70,000 years ago. It is often unclear why they chose to leave. It could be because food was scarce, or there was internal conflict among the early humans or because many humans were just curious as to what lay up north.

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                            When Did Humans Evolve into Different Races

When they subsequently decided to move northward around 70,000 to 60,000 years ago, it took possibly 15,000 to 20,000 years before our black ancestors from Africa evolved into Asians in Siberia and Caucasians in Europe. 

By roughly 40, to 50,000 years ago, we humans had become different races. Why was that the case? Because humans have difficulties living with both too much sunshine or too little sunshine, they evolved very different skins colors to cope with their changing environment. 

While the topic of race has often generated a lot of controversy and conflict, we need to recognize that racial traits are merely evolution’s way of enhancing the ability of people to adjust to their environment. In a much earlier post I spent a lot of time explaining why those different racial traits evolved. To not repeat myself too much, I have briefly summarized that material in the following section.

As I explained in that earlier commentary, when early humans first lost their body hair around 2 million years ago they evolved a dark skin to protect their bodies from the harmful radiation from the sun. Since all early humans lived in Africa, the black race was the first race to develop. But as our black ancestors moved north, they eventually shed their dark color and evolved into our two lighter races of Caucasians and Asians. 

The Indians of America are an offshoot of Asians. Because they traveled quickly through Siberia on their way to Alaska, they did not acquire all of the facial and bodily characteristics of Asians. But their straight black hair and their skin color which lead movies in the 40s to describe them as redskins show their affinities with Asians.

a.What Color will people be?

The general rule of thumb is that if you evolved near the hot equator you will have dark skin. 

If in contrast, you move all the way north to Norway, you are only likely to experience 6 to 8 hours of sunlight in winter. If you live even further north, you will experience even less sunlight with some areas experiencing the polar night when the sun never rises above the horizon. Becuse of their lack of exposurte to sunight these  people are in danger of receiving too little vitamin D raising questions about their long term health. To correct this situation the vast major of these people quickly lost their dark skin and became blond and very white Caucasians.

Finally if people evolve in the mid latitudes such as Siberia, they will also evolve lighter skin coloring like Asians. Even among Asians there are distinct difference in their color. If you are northern Asian either Korean or Japanese, you are likely to be very fair skinned. If you ignored Asian’s facial or bodily characteristics you would probably have trouble distinguishing the skin color of some one who is from northern Asia from someone who is from Europe.  But if you look at the color of Asians who live closer to the equator such as the Philippines or Malaysian people you will find that people have darker skin coloring. 

b.The Issue of Height, When will People be Lanky”

Similarly if you look at bodily characteristics of people you can also tell what kind of climate they evolved in. 

If you are raised in a very hot climate like Kenya in East Africa or West Africa you will find many tall lanky individuals.  Why does evolution produce this kind of body structure. 

c.Surface Areas to Volume Ratios.

It has everything to do with the surface ratio to volume of your body which helps determine the amount of heat you lose to the environment. If you are lanky, you will have a high surface area which means your body will easily radiate heat to the outside. If you are also working hard and actively perspiring, you will also lose a lot of body heat. In a very hot dry climate this body structure will help keep you cool and make your life on the hot African savannah bearable.

However if you had the exact same body structure while you were growing up in a very cold Siberia, you would feel miserable. While tall lanky people would be suffering, individuals with more compact bodies would have a lower surface area to volume ratio and thus less likely to lose much bodily heat. A bodily structure that is rational for East Africa would have negative effects on people living in a cold Siberia.

We thus find that the tallest and lankest people will be from hot Africa and the shortest and least lanky types will have evolved in the much colder climate of Siberia and Asia.  In contrast Caucasians will fall somewhere in the middle but closer to the body features of Africans than Asians.

d.A Summing Up

When you see someone, and you see their skin color and bodily size you can tell where their ancestors originally came from. If they are of dark skin color, they are from the equator and if lighter color from more northern latitudes. Conversely if they are tall and lanky their relatives evolved in a relative hot climate while if they are shorter and have more compact frames, they probably evolved in a very cold climate. 

While racial differences have been a source of conflict for centuries, evolution generated variations in skin color to merely help people better adapt to their local environment. Aside from the influence of evolution, mere racial differences have no political, religious or social significance. 

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                             We may Have Come Close to Dying Out

While their early record of migration seems to suggest that humans were thriving as they spread around the world, that apparent success almost did not happen. About five thousand years before early humans began their trek northward the total human race came close to dying out.

Because biologists find that all humans are closely related when they compare their DNA, many biologists and paleontologists  think that around 75,000 years ago modern humans came close to dying out.  This period was one of the 15 period of massive die offs that have occurred over the last 500 million years but it was not one of the top 5 major periods of extinction in which 70% to 90% of all species passed away.

It is thought that this period of extinction which seems to have adversely hurt humans the most, shrank the human population to under 10,000 people, which explains why biologically most humans have very similar DNA.  There are various theories as why humans almost died out including a massive volcanic explosion which blocked sunlight for several years to a unusual cold turn which killed off much of the earth’s vegetation. 

a, A Change of Diet

Fortunately, early man adapted by changing his diet. For most of his existence the earliest species of Homo Sapiens had relied on meat from the numerous herds of animals like the wildebeest  that had developed on the African savanna. Whenever possible early man also ate fruit or tubers or other plant material if they could find it. 

But as the vegetation in northern Africa dried out early man migrated south to South Africa. where apparently running out of options, they tried harvesting sea food from the oceans. By changing our diet, humans may have managed to survive a climate change that threatened to wipe out our species. Individuals, who had been primarily meat and vegetation eaters, finally chose to diversify their diet by consuming shellfish during these dire times.

While today many people enjoy sea food, they may not realize that food option was a relatively recent development that our ancestors adopted out of pure necessity.

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                                    Issues to Explore in the Future

While the evolution of our physical characteristics was certainly an important part of becoming modern humans, we still had many unanswered questions. Those include the following three topics:

a.How Did We learn to Talk

First, they include the issue of how we learned to talk. In the next couple of posts I hope to explore this topic in more detail.

b.How Did we Become Smarter

Secondly, they also include the issue of how we humans became so much smarter. While Lucy had a brain of 375 to 475 cubic centimeters, a modern human has a brain of 1260 cubic centimeter which is almost 3 times larger. Paleontologists have debated for years why humans managed to become so much smarter. 

1) Did the Inconsiderate Nature of many People make us Smarter.

Ironically one of the leading causes of human intelligence may have been the fact that modern humans realized that the fellow humans beings were not necessarily all that considerate or kind. 

While early man lived in the forest, he probably lived a somewhat independent and isolated life. But when he ventured on to the savannah of east Africa, he found himself now dependent on other human beings for security and well as for assistance in hunting big game. In this new environment, it was important to know what people were likely to be long term friends. 

People may thus have become smarter because they were desperately trying to figure out who they could trust, or whether their alleged friendships were merely strategic alliance that would be quickly forgotten when they no longer served a useful purpose.

It is ironic that one reason why humans of all species are the smartest is that they knew they had to be careful when dealing with fellow members of their species who were often self interested and not all that considerate.

It is thus surprising that our need to figure out who to rely on, eventually so enriched our brains, that we later could figure our how the universe works. Psychological Intelligence may have also lead to scientific intelligence.

c.How Did we Develop two Parent Families?

Finally a third issues is why did humans form long term two parent relationships. Our two closest ancestors have very different sexual relationships. Chimpanzees are very promiscuous and often hostile in demanding sex with female chimpanzees. In contrast great apes live in harems in which a silver back monopolizes the sexual behavior of multiple females. Given the different paths choose by our closest primate relatives it is interesting to understand why humans choose to live in very different types of families..

                                                      A Post Script on Evolution

Before discussing the above topics maybe we should spend more time discussing the phenomenon of evolution. I mention this become two of our best friends, who were also the husband and wife builders of our house, told us one night at dinner that they did not believe in evolution. Our builder friends are very bright and well informed and known a lot about architecture and structural engineering, but they have no faith that evolution explains anything.

When I wrote that section on the development of man, I realized that probably many of our classmates probably had their doubts that humans had evolved from Lucy,

I thus realized that maybe I need to do a better jobs presenting the outlook of evolution before describing how modern man evolved over time.

However, since old age is catching up with me, and I’m feeling somewhat tired, it may take me a while to develop all of the above themes. 

Bill Kelso

                                                        VII

                                  When did Humans Began to Speak

The issue of when people began to talk is a controversial topic and there is no consensus as to what time period Homo Sapiens began to speak. But one of the most popular options argues that people may have begun to talk at the same time that the famous Paleolithic paintings at Lascaux in France and Altima in Spain occurred between 35,000 and 15,000 years ago. Many paleontologists think that 20,000 year period was so creative and artistic because humans had finally improved their ability to communicate with one another.

                                           Four Forms of Communication

But among paleontologists there is agreement that before humans could actually speak, humans may have devised much earlier forms of communication.  Below is a list of the options.

                                             1.  Eye and Eyebrow Movements

                                             2. Gesture Languages

                                             3. Singing

                                             4. Human Talking

Again all of these options are hotly debated these days by paleontologists.

1.Our Eyebrows and Eyes

Among early humans they may have indicated their feelings by moving their eyebrows and focusing their glaze on people.

Today if we are surprised or pleased with an action, we often raise our eyebrows to express our sentiments. Similarly, we today believe that your eyes can express a range of emotions include fear, happiness uncertainty or boredom. It  is very clear  that our eyes are a nonverbal means of communication. 

If we are upset or concerned with the behavior of another person, we may express our emotions by either blinking or dilating our pupils. When you feel affection for someone your pupils may dilate which is known as puppy love. Conversely if you feel stress, you may blink more often. When we are exasperated with someone we may even roll our eyes, or shift our eyes to the right or left if we are trying to hide somethings. If we are suspicious or a person, we may find ourselves narrowing our glance to indicate our sense of disbelief.

a.The Importance of Having White Eyes: The Sclera

One factor that enhances the ability of our eyes to communicate with other people is the makeup of our sight. Among most animals the most visible part of their eyes is the iris and the pupil. The iris is the colored part of your eye that determine the amount of light that enters the eyes. The pupil is the circular dark opening in the iris that controls the size of the iris.  

b. The Sclera

However, human eyes are different from the eyes of most animals in that our eyes are surrounded by a white fibrous tissue called sclera. Paleontologists have often asked why that is the case. 

Because all early humans had dark skins, the sclera magnified the importance of their eyes. With black skins an individual’s white eye would quickly have caught everyone’s attention and facilitated his or her opportunity to express his emotions. Humans may have evolved white eyes because it may have enhanced their ability to communicate with other individual before they had learned how to talk.

c.How Our Dogs Biologically Copied Us

Because our white eyes have been such a notable part of our appearance it may have caught the attention of our earliest hunting companions. When humans domesticated wolves and bred them to become more pliable dogs, they naturally had to communicate with their new pets. In the process dogs acquired an enhanced muscle in their eyebrows which enabled them to pull their eyes back to their ears. In the process the dog’s eyes became bigger, and even more importantly, the dog’s eyes now revealed their white sclera. 

As dogs saw humans communicating with one another using their eyes, they biologically may have modified their eyes to become part of the conversation.

2. Our Gestures

Besides using our eyes, a second language humans may have employed early in our development may have consisted of hand or body gestures. By pointing or making hand signals people can convey a lot of information. 

For instance, by use of our hands we can attract people to ourselves or tell them to follow us. We can likewise use our fingers to point out either dangerous events on the horizon, or possible sources of food today.

Because we may have relied on gestures for such a prolong period of time, when we finally acquired the ability to talk, our speech chose to use the language of hand or body gestures to make an argument or express an emotion.  While we could now use sounds rather than gestures to express ourselves, our conversations preferred to mimic our previous reliance on physical gestures to make our point.

For example, we often say “I can’t grasp what you are saying.” Or “Hold on, I am not following you.” Or we say “you lost me or “I can’t keep up with your thinking.” If we have difficulties with a topic we often ask our partner ”Will you give me a hand?” or “I could use a helping hand”. If someone performs well we might reply that your behavior “left me breathless.” If you are going to do something risky, you might respond” I’m going to stick my neck out.” Or we say you are running me ragged.”

Even the lyrics of songs often are based on hand gestures. The most obvious examples is Sam and Dave’s popular tune “Hold on, I’m Coming”.

3. Singing. 

A third way of communicating with people is to sing to them. We often think singing must have come after we learned to speak, but there are many animals such as birds and whales who communicate only by singing. It is possible that that was the case with humans.

But while singing is a great way of communicating with a large group of people, it is not a very effective means of communicating with just one person. Today many paleontologists think one reason why humans became so smart is that we had to figure out who we could trust. To achieve that goal you would often want to have a private conversation with another human being about a third party. Given this desire to have more subtle talks with our fellow humans we may have evolve speaking to initiate conversations with just one other person.

4.Actual Speaking

a.Tonal Languages

The best evidence for this proposition that singing preceded individuals talking is the simple fact that roughly half of all languages involve tones. In Africa many people from West Africa have languages with absolute tones while in Asia the Chinese, Tibetans and Vietnamese use directional tones in conversing with one another.

b. Pitch Accent Languages

Besides tonal languages, many other languages use pitch accents to convey meaning. Pitch accent is a phonetic feature of certain languages such as Japanese in which pitch comprises a fundamental component of the pronunciation of words. In the case of standard Japanese nearly every word in the language is consistently pronounced with one of four main pitch accents. 

You can thus think of the different tones in Chinese or the pitch accent in Japanese as similar to different melodies in a song, a linguistic feature left over from an earlier time in which humans communicated with each other by singing.

c. Flat Tone Languages: Were they the Last Languages Invented?

Finally besides relying on the contour tones of the Chinese or Japanese accents, Europeans invented a third form of language using flat tons that are widely spoken in America as well. Given the unusual nature of western language, it is possible that the languages of  Europe and America were the last and final form of spoken language to have evolved.

Bill Kelso

                   When did we Acquire our Specific Languages?

If the question of how we acquired the ability to speak is an interesting topic, the subject of why we speak our present array of languages is another fascinating piece of social history. In learning where we acquired our languages, we also will gain some insight into where our earliest ancestors came from.

As we will explain in a later post, humans began to create more complex civilization around 4 to 5 thousand years ago. During this process humans develop two competing types of economies or civilizations. They were respectively sedentary farming communities and pastoral nomadic communities in which people survived by herding animals such as horses, camels or sheep. It is the conflict between these two different civilization that determines which languages most people speak today. The winners in this conflict between two opposing civilizations also determines where your earliest ancestors came from.

a.Sedentary versus Pastoral People

But before delineating how this conflict shaped our languages, we need to have a better understanding of how these two civilizations worked. For instance, the sedentary people who often lived in fertile valleys or in delta regions associated with a river created cities that were supplied by their farming communities.

 The pastoral people, in contrast, had to live in grasslands where their horses or camels could survive by grazing.  In Eurasia, this grassland is called the steppe, and it is a vast belt of grazing land which stretches from Japan to Hungary in Europe. If you hit the link below, the green stripe across Eurasia is the steppe of Asia which is the home of two pastoral people, the Turks and the Mongols. A second home of nomads is the Arabian desert of Saudi Arabia where Bedouin tribesman live and raised camels in a variety of oasis in the desert.

                                    The Steppe in Eurasia, home of Pastoral People

A third home of pastoral people is the Pontic Steppe which is the western end of the steppe that covers all of Eurasia and it lies to the east of Europe and north of Saudi Arabia. It was also home to the first horses that were eventually introduced into Europe.

As soon as this division occurred between these two types of communities, human history became a violent contest between nomadic pastoral people and their sedentary neighborhoods. This conflict which lasted for over 5000 years eventually determined what types of languages the various people of Eurasia eventually spoke.

b.The Three Nomadic Pastoral People

In the above three cases, the pastoral people constantly attacked the sedentary civilizations that were their neighbors. To help remember these groups the following outline may be of some assistance. As you probably know the Chinese built the Great Wall to keep the Mongolian pastoral people at bay. But in contrast the sedentary civilizations next to the Arab Bedouins as well as the sedentary societies of Europe next to their Indio European enemies neglected to build any kind of barrier to keep their hostile neighbors contained.

1.                                                                 B.

Sedentary Societies                                         Pastoral Societies

1.China                                                            Mongols and Turks Attack China

Eastern Eurasia

2.Middle East                                                      Arabian Bedouins Attack the Middle East.

Middle Eurasia   

3.Europe                                                              Indo Europeans Attack Europe

Western Eurasia.  

Historically when the two civilizations clashed, if the nomadic pastoral people defeated their neighbors, they imposed their language as well as their ethnic identity on the conquered people. In the process they abandoned their pastoral lifestyle and created their own sedentary communities as was the case of the Middle East and Europe.

1)The Chinese Language

But if we examine these three clashes separately, we see that the Chinese were generally successful in defeating the attempts of the Mongols to capture their homeland. As a result the Chinese were able to retain their traditional language of tones. The one exception to this historical record was when Genghis Khan conquered China in the 13^th century. But his rule lasted less than a century and the Chinese eventually regained their independence. If you hit the following web site you can get a picture of steppe which was the home of the pastoral people of eastern Asia.

                                                  The steppe of Central Asia

2)The Arab Language

In contrast if we look at the Arabian Peninsular in Eurasia, the countries surrounding Saudi Arabia were eventually conquered by their pastoral neighbors. In the process the people of Egypt and Mesopotamia and northern Africa, who never once thought of themselves as Arabs and spoke their own languages eventually adopted the language as well as the identity of the Bedouins  or Arabs from Saudi Arabia. In contrast to the Mongols the Arabs attacked with camels as well as horses. If you look at the following two websites you can get a feel for the original home of the Arabs.

                               The Dry home of the Bedouin who created the Arab states

                                 The Home of the Arab Nomads who create the Middle East

3) The Indo European languages of Europe

Finally the last major conflict between pastoralist and sedentary societies occurred at the western part of Eurasia in an area called the Pontic Steppe, an area just outside of Europe. Prior to 4500 years ago, nobody in any area of Europe spoke any of the 24 major languages spoken by Europeans today. 

In Europe as in the regions outside of Saudi Arabia, a large group of pastoral nomads whom we call Indo Europeans, started raiding and attacking Europe.  Unlike China which was fairly centralized, Europe, which was also highly fragmented, made no effort to build a Great Wall to protect their part of the continent from attacks from their aggressive neighbors.  After a while numerous Indo-European tribes began assaulting and eventually conquering Europe. 

If you are of European heritage and you relatives came from countries like England or Germany, your original ancestors lived on the steppes of western Eurasia. If you also want to see either their homeland or what life was like on the steppes of Europe, hit the following two websites 

                                         Map of the Homeland of Indo Europeans

                          The home of the Indo Europeans who gave us our Language

Because the Indo Europeans were made up of many tribes, they all spoke slightly different languages. The first wave of Indo-European invading Europe roughly 4500 years ago, spoke Greek and Latin, and eventually changed their pastoral ways to build the classical states of Greece and Rome.

Two thousand years later a second wave of Indo Europeans attacked Europe, this time displacing the earlier settlements of Indo Europeans. In place of Greek and Latin, the new invaders from the Pontic Steppes primarily spoke German and imposed their languages on the countries that we today call Germany, Scandinavia, the Netherlands and England. The word English is actually derived from an German Indo European tribe called the Anglos who conquered England after the fall of Rome. Likewise the name for France is derived from another German Indo European tribe called the Franks. Right behind the German speaking tribes were tribes speaking the various Slavic languages.

For those in our class with a European heritage, our ethnic identity as well as our language thus came from the successful attacks and conquests of a second wave of pastoral people from the Pontic Steppe. Our nomadic ancestors who conquered Europe and intermarried with the local population created the present population of Europe.

Bill Kelso

                                                         VIII

                  When did Humans begin to Buiild Civilizations                          

After living a rather simple and primitive life style for close to 200,000 years, when the Ice Age which had dominated the planet for the last 2 million years finally ended 10,000 years ago, man for the first time began to farm and later create small villages.

Finally after years living as primitive farmers and horticulturalists, humans started to build cities some 5000 years ago, creating in the process the earliest civilizations in Egypt, Iraqi, the Indus River Valley or Pakistan and Northern China. 

As noted above, these earliest civilizations eventually had to deal with the attacks by pastoralist. Depending on how successful they were in defending themselves, areas like the Middle East and Europe were eventually conquered and adopted new languages and even new ethnic identities while an area like China maintained her original languages and traditional heritage.

                                When Did America Become a Major Political Power

                                                                   (1)

                                    When Was the Country of America Created

Among the planet’s numerous countries, America was very late to develop and become a major power and civilization, accepted and respected by other nations. It wasn’t until about 350 years ago that the Pilgrams arrived and established a colony in Massachusetts. It then took another 150 years before the US became an independent country, no longer under the control of Great Britain. But even more importantly 180 years had to elapse from the success of George Washington at Yorktown before the McClatchy class of 1963 graduated and left its impact on America.

                                                                      (2) 

                            When Did We Become an Advanced Technological Society

Our generation has been fortunate to be born at the end of the first major period of industrialization in the world. For instance, American homes have only had electricity for around 130 years and refrigerators which were invented around 1913, for about 110 years. This same period saw the invention of airplanes, bicycles and automobiles. 

Likewise, it was not until the late1980s or 1990s that personal computers were widely available, followed by the internet 20 years later.

                                                                     (3)

                             Comparing the Wealth of Americans with other Countries

The growth of industrialization also led to the growth of an incredibly prosperous United States. If you look at GDP per capita the major countries of Europe have a per capital that is about 50% to 66% of the US. If you average the per capita GDP of Latin America, Africa, the Middle East and Southeast Asia, our GDP per capita is roughly 15 to 20 times greater than these four continents.

For instance, while the GDP per capita of America is $81,000  in 2023, that of the rest of the world is considerably smaller. 

                                                   America                      $81,000

                                                   Great Britain               $62,571

                                                   France                         $49,571

                                                   China                         $14,400

                                                   The Middle East           $13,700.

                                                   Latin America              $10,377

                                                   Southeast Asia              $5,810

                                                    Africa                         $2,950

                                                     India                          $2,410.

While it is true that not all Americans have prospered over the last 100 years, especially the working class whose financial position was undermined by the deindustrialization of America, the overall record of Americans looks very impressive when compared to other nations.

                                                                     (4)

                                      What is the life Expectancy of Americans

Besides being fortunate to live in such a wealthy and comfortable country Americans have also seen a dramatic increases in the number of years an average American lives. If you look at the figures below you will see than in 1900 or 125 years ago the average American would passed away at age 43.7. Today the average life expectancy for a man is in the high 70s and the low 80s for a woman.

The fact that so many members of our high school class are still alive indicates that we have enjoyed a more comfortable and healthier life stye than preceding generations including that of our parents and grandparents

                                Year                            Male                            Female

                                 1900                            46.3                             48.3

                                 1920                            53.6                             54.6

                                 1930                            58.1                             61.6

                                  1940                            60.8                             65.2

                                  1950                            65.6                             71.1

                                  1960                            66.6                             73.1

                                  1970                            67.1                             74.7

                                  1980                            70.0                             77.4

                                  1990                            71.8                             78.8

                                  2000                            74.1                             79.5

                                   2010                            76.2                             81.1

                                   2020                            74.5                             80.2

                                   2023                            75.8                             81.1

                                                                        (5)

                                               A Quick Overview of our Life 

If you look at the above data, our generation has lived an enviable life. If you compare Americans today with the history of humans who first appeared two million years ago, as well as with people in other countries today, we have enjoyed a comfortable and prosperous life style for an infinitesimal brief period of time. If you do the math, modern humans, who evolved 200,000 years ago from the original creation of humans 2 million years ago, have lived in sophisticated communities for less than 3% of our existence on the planet. That statistic makes us unique among all of the humans who have ever lived.

Bill Kelso

                                                               IX

                                   How to Make Sense of our Universe

After what was probably a too long review of our universe and planet, it is maybe time to ask what it all means. An interesting question is can we make sense of our universe and our unique origins. I think if we try to quickly sum up events, perhaps five topics stand out.

                                                                (1)

                                    Finally We Can Understand Our Past

The first significant development is the remarkable advancement the natural and social sciences have made in the recent years to finally understand 1) first our home, the universe, solar system, planet and 2) secondly the origins of our species, Homo Sapiens. 

Despite our earliest emergence from the rain forest of east Africa some 5 million years ago, humans have only come to appreciate and understand how complex our history is within the last 100 years or so. Probably 75% of everything we know about our world today was discovered since the start of 20^th century and perhaps 60% of that knowledge was generated after the 1960s, the decade in which we graduated from high school. In this sense we are the first generation of humans to finally have a good grasp of both our home and our origins.

                                                                 (2)

                                            Our Changing View of the World

Secondly, the recently findings have completely upended how we view our universe. Prior to the years we graduated from McClatchy , the natural sciences believed that we lived in a fairly stable world in which the universe, the continents and even life on earth experienced little of no change. 

The subject of evolution which was a radical idea in 1860s seemed to apply only to the area of biology.  In the realm of astronomy or physics and geology there were universal laws that attested to the unchanging nature of our planet. 

But by the late 1960s through the 90s, all of the above ideas were overthrown. As we mentioned earlier the idea of punctuated equilibrium now seems to govern the field of physics, as well as geology and biology. That idea suggests that while at time the earth as well as the universe experienced periods of stasis, or stability, at other times it faced dramatic rebirth or destruction. The laws of evolution now were true of all realms of our existence. Besides life on earth, the universe as a whole, galaxies, the planet and even our own species was constantly undergoing periods of radical change.

But what was most startling was the discovery that our universe and everything in it was maybe a once off event that would eventually die off. Whether we looked at the stars, our galaxy, the milky way, or our solar system, scientists could estimate an expiration date in which everything in our universe would eventually disappear.                             

                                                                  (3)

                                      Our Existence May Owe a Lot to Chance

Thirdly, as remarkable as was the discovery that our universe would eventually cease to exist, was our observation that the creation of advanced forms of life on our planet was perhaps an accidental event. If you are of a religious bent, this conclusion would naturally be troubling. 

To cope with the new findings of the natural sciences today, even the Catholic Church now argues that it accepts the idea of evolution. But in so doing it may be altering the way the church has traditionally seen God. If a Supreme Being is managing the universe, he is acting more like a distant watchmaker rather than an emphatic being who cares about the plight of individuals.

While a watchmaker designs the universe and even winds the clock to start it ticking, his involvement in the universe is minimal once the clock starts working.

While the watchmaker thesis is very possible, the history of the universe seems much more contingent in nature or governed by chance. That is accidental events rather than an overall design by a supreme being seems to both explain why life arose in the first place and why humans first appeared in Africa.

Because we have covered so much material, the following list will hopefully indicate all of the unusual and complicated events that finally lead to life on earth and especially the development of our own species

a.Special Events that Made Life Possible

14.7 Billion Years Ago

Naturally the first and most important question when we try to understand our place in the universe is to ask why our universe was created in the first place. As I indicated in an earlier post, one of the most interesting questions in philosophy is why there is something rather than nothing. Before the big bang there was nothing where we currently live. Was the creation of our universe something special or as part of a long-term never-ending cycle of universes developing and dying only to be reborn again. 

Maybe life has continuously evolved in a variety of universe before eventually finally passing from the scene. The questions are interesting but unfortunately, we have no satisfactory answers about the creation of our universe.

13.9 Billion Years Ago

A related issues is the creation of our Milky Way Galaxy. It occurred 800 million years after the creation of the universe. But while our galaxy was developed early in the universe our Solar System was not born until roughly 9 billion years later.

6 Billion Years Ago

Finally after billions of years the stars of our universe and galaxy finally developed complex chemicals that would support life. It now appears that whenever a new universe is born, its ability to support complex forms of life must wait billions of years until its stars have evolved to the point where it is fusing together chemicals like silicon and carbon. 

Until that point is reached, our solar system, as well as any other solar system in our universe, will be sterile, lacking the chemicals necessary to make complex forms of life like us.

4.7 Billion Years Ago I

Besides the creation of our universe, the second most important development is the creation of our solar system. However, besides its origins, what is unique about our Solar System is its fortuitous location outside the major spiral arms of our galaxy. If our Solar System had been born in one of the major arms of the Milky Way, it might have been destroyed by some nearby dying star.

4.7 Billion Years Ago II

Besides the fortuitous birth of our solar system, what is remarkable is the fortuitous nature of our planet. 

1. For instance, the location of our planet within the Solar System is key to its ability to support life. The earth is neither too near nor too distance from the sun and thus neither too warm nor too cold to sustain animal and plant life forms.

2. Secondly it is notable for its size. If our planet had been either much bigger or much smaller, life might have died out by now as is the case with Mars. If  much bigger gravity would have made it too hard to walk and live a productive life. If much smaller it might have lost its molten center and subsequent magnetic field which protected our atmosphere.

3.Thirdly is earth’s watery nature. If water had not been transferred from other planets in our solar system to our earth, life would never have evolved on earth. Water is probably the main key element necessary for life to take hold and develop more sophisticated forms of existence.

4.4 Billion Years Ago

But the nature of our planet is merely one of many lucky events that humans on earth have benefited from. If the planet Theia had not crashed into our planet creating the moon, the rapid spinning of the earth might have made it impossible for any advanced forms of life to evolve.

3.3 Billion Years Ago

Similarly at about 3 billion year ago, the  molten interior of our planet began to generate the magnetic field which protects our atmosphere from being blown away by the sun.

3 Billion Years Ago

About 300 million years after creating the magnetic shield our molten earth also started the process of plate tectonics. But the early process of plate tectonics did not create the many continents we see on the earth today. Because the initial rocks created by plate tectonics were very dense rocks called basalt, they eventually sank to the bottom of the oceans..

2.5 Billion Years Ago

However, about a half billion years after the start of plate tectonics, the clash of the various plates produced a new kind of rock called granite that is so light it floats to the top of oceans. This is the start of the creation of continents on planet earth which now cover 29% of the earth’s surface.

If this new rock had not been developed, human forms of life would never have developed on land on our planet. At best complex forms of life might have evolved but they would have consisted of maritime animals such as fish, and perhaps dolphins and whales.

Once again it is interesting how the existence of human life depends on geological changes in the planet. The second major geological change will be the creation of the rift valley in Africa some 5 million years ago.

2 Billion Years Ago

Another factor that facilitated the growth of sophisticated forms of life on the planet was the complex relationship between our atmosphere and the sun. As the sun over time grew hotter, its potential harmful impact on the start of life on earth was softened by the decline of CO2 in our atmosphere. As the sun warmed up the decline of greenhouse gases like CO2 helped  keep the overall temperature fairly stable.

500 Million Years Ago

But perhaps the major reason why we humans eventually appeared on earth is due to the Cambrian Explosion of complex life forms 500 million years ago. This explosion occurred because photosynthezing bacteria had created enough oxygen that the earth could now support more complex forms of life.

245 to 225 Million Years ago

Around 240 million years ago both dinosaurs and mammals, our direct ancestors, appeared on earth. But since mammals were small rodent like animals, they basically stayed out of sight during the day when dinosaurs ruled the world. 

66 Million Years Ago I

If it were not for one unexpected asteroid hit on the earth that wiped out the dinosaurs some 66 million years ago, mammals may have remained a minor life form and never have evolved into humans.

60 Million Years Ago II

As the dinosaurs died off, evolution quickly promoted a burst of life to fill all of the available niches, including the growth of numerous 4 legged predators

58 Million Years Ago

As the number of mammalian predators proliferated, our ancestors took to the trees to find safety.  In the process our earliest mammalian ancestors eventually evolved into the three species of monkeys, chimpanzees and proto humans.

50 Million Years Ago

After the demise of the dinosaurs the level of oxygen which had reached 35% of the atmosphere declined to around 10%.

If evolution had never developed the diaphragm or respiratory pump in mammals, our species may have lacked the energy necessary to eventually develop a complex society in an atmosphere of low oxygen.

30 Million Years Ago

In addition, were it not for the growth of oxygen in our atmosphere to 21% of the air 30 million years ago, early humans, even with a air pump, would have lacked the energy to create any kind of industrial civilization.

5 Million Years Ago

But even more importantly if our planet never had a molten center that constantly consolidates and tears apart continents, it would never have created a rift valley in Africa five million years ago that would dry out the rain forest of Africa. It was this fortuitous event that forced our earliest primate ancestor out of canopy of the rain forest on to the semi dry land of the African savannah. What at first appeared to be a minor geological development, turned out to be a seminal event in the creation of our very own species.

2 Million Years Ago 

Around 2 million years ago, as humans replace Australopithecus as the major form of proto humans on earth, humans began to hunt and cook meat which dramatically changed our appearance. Because we ate softer foods, our faces become flatter and our noses which had been embedded in our face now became a major part of our overall appearance.

75,000 Years Ago 

Even with the demise of our dinosaurs as competitors, humans might have died out 75,000 years ago when our numbers declined to under 10,000 people in another one of the earth’s massive extinctions. As the continent’s vegetation and animal life declined, the ability of we humans to cultivate another source of food, sea food, probably saved us from extinction.

                                                               (4)

                                    Why the Future May be Problematic

A fourth conclusion to draw from the earlier posts is that the future of our planet may be problematic. However, it is always a risky business to try to predict the future. But we also have to realize that if there is one characterization that most adequately describes what has happened over the last 14.7 billion years, it is that change, dramatic change, rather than stability governs the universe. Many of those changes suggest that the future may prose serious risks for future generations of humans.

a.Changing Climate

Among other topics we have discussed, we have seen that the earth’s climate has been very volatile, ranging from a planet totally covered in ice to a planet significantly hotter than today. If in the future, there were another ice age like the last one that covered New York City and Chicago the American economy would be devasted.

b.Changing Oxygen Levels

Similarly we have seen that oxygen levels have varied from a low of 6% to a high of 35% to our present 21%. When  oxygen levels drop, the ability of humans to functions at a high level of energy will automatically decline.

c.Massive Die Offs

Finally our earth in the last 500 million years has experienced 15 major dies offs, one of which almost wiped out all humans 75,000 years ago. While paleontologists are often divided as to what causes the die offs, the causes seem to be events that humans have no control over.

It is important to realize that if these changes occurred in the past they may very well happen in the future. While these changes may not result in the die off of the human race, they may make it difficult for the current world population of eight million today to enjoy a very affluent lifestyle. For most of our history, the vast major of people were incredibly poor living as hunters and gathers. Only in the last 130 years since the age of industrialization have a sizeable number of people enjoyed a comfortable life in which they did not have to struggle to survive.  But if our earth’s climate, oxygen supply or fatality rate increases, that situation may change.

To have a balanced discussion we must admit that we humans could develop the technology to cope with the above possible difficulties. For instance,  humans may be on the verge of creating yet another new species of human beings. Whether it involves people choosing designer genes to implant in their children or installing chips in their brains, people of the future may have very different personalities and lifestyles from those we enjoyed. If AI or artificial intelligence takes off, the future generation of humans may be better prepared to cope with a changing future than we presently are. Fortunately, we will not be around to worry about what the future holds.

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                                                    What is our Situation

Finally a fifth topic to draw from our history of the universe is the realization that our journey on this planet has thus been an unusual and fortuitous adventure. On so many occasions things could have turned out very differently from the way they are today. In light of our unique history, we have to realize that our existence in the universe has been brief and fleeting in nature. But we should realize that in a very large and often impersonal universe we have been fortunate to enjoy the gift of life.

a. Part of a Grand Experiment

While most of us are at that stage in life in which we probably only have a few more years to live, we should be thankful that we had the experience to enjoy life. If our universe is a once off event that will eventually disappear forever, we should be grateful that we were part of that experiment. If life were contingent on numerous accidental event, we should be thankful that we were the beneficiaries of those chance events. 

b. A Stable Period of Life

But perhaps the major event that we should be thankful is that we lived during one of the more stable periods of life. Even since the last ice age ended, humans have lived through a golden age of prosperity in which people left their hunter gather background behind them and build large complex civilizations. 

c.A Wealthy and Comfortable Period of Life

We have also enjoyed being part of an advanced society in which people can watch streaming movies, listen to a diverse array of musical genres and enjoy major sporting events. Over the last 5 millions years, only a small sector of the world's population have ever enjoyed such benefits.

We in our McClatchy class were doubly lucky in that we were born in the United States which historically is one of the wealthier and most sophisticated societies ever built. In contrast to the 99% percent of the people who preceded us or who currently live in countries outside of America, we have been privileged individuals. For that we should all be thankful.

If our individual time will soon be up, we should be grateful that in the history of mankind, we stand out for having enjoyed such a great life.

Bill Kelso

While the above posts probably did a better job exploring the nature of our home including the universe and our solar system, our discussion of human beings was rather incomplete. In future posts I hope to spend more time on the process of biological evolution and the origins of man. Besides the development of punctuated equilibrium, biology has gone through two other revolutions which have significantly changed our view of how mankind evolved.

Unfortunately as I approach 80, I have been slowing down. I need to take a break before we discuss in more detail how humans have changed over time.

Bill Kelso

                                   Where did Humans Come From?

After I posted a recent article on the origins of man, based primarily on recent archeological digs in Africa, I decided to look at American attitudes towards evolution. I quickly found that the doctrine is not all that popular.

Instead Americans seem to have three views of the subject and each view has about a third of the public supporting it. 

                                                              (1)

                                              The Permanence of Man

The first group, which pretty emphatically rejects evolution, says that humans have always existed in their present form since the beginning of time. They reject the idea that the complex nature of humans could have been produce in a short period of time by evolution. This view which has an ancient pedigree is best expressed in Michealangelo picture of God giving the gift of life to man. This view insists that man has always looked the way we presently see him.

                                                 God giving the gift of life to Adam

                                                                 (2)

                                                 Divinely Inspired Evolution

A second view accepts the idea that man has evolved over time, but they argue that it is not Darwin’s idea of natural selection that has shaped man. Instead they insist that evolution is more divinely inspired and reflects God’s will. However there are two versions of this second approach. 

The first version argues that God is a distant watchmaker who winds up the process and then lets it run its course. This view is also called Deism and was the belief of our founding fathers such as Washington and Jefferson.

A second version of a divinely inspired form of evolution is called intelligent design and it also believes that man has evolved over time. But they see God as directing and actively involved in the process of evolution rather than as a watchmaker who once he starts the process of evolution becomes a distant observer. Some argue that God is a sculptor rather than a watch matcher who actively shapes the outcome of evolutionary change.

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                               The Interaction of Natural and Biological Forces

The third approach, which about one third of Americans supports, argues that man as well as all forms of life have evolved over time and all from the same original source of life. Their main difference with the second approach is their belief that the various biological, physical and geological forces that makeup our world are all independent of one another and operate on separate principles of nature.

In Darwin’s theory of evolution, various organisms of life periodically experience genetic mutations. Natural selection then takes over and either accepts or rejects these mutations depending on whether these mutations enhance or undermines the organism’s adjustment to its environment.

The traditional biological theory of evolution would argue that all the factors that make up natural selection such as the origins of plate tectonics, the climate, the action of asteroids are all separate from one another and operate independently of each other.  

They would reject the idea that the diverse forces of mother nature are part of some master plan. While they would naturally agree that the above factors would eventually interact with one another and impact the world, they would insist that the interactions that produced evolutionary changes were often accidental or contingent in nature rather than part of some intelligent cohesive objective.

Unfortunately there is no way to prove that either one of the above two approaches is superior to the other. Proponents of modern evolutionary theory will often cite a famous medieval argument called Occam’s razor which states that if two theories are in doubt, you ought to choose the simpler one. While this theory is often cited it does not offer conclusive proof that one approach is better than another.

                                                                 (4)             

                                               What the Poll Data Suggests.

If the above polling data is correct and our class mirrors the country at large it means that probably over a third of our class thought the post about the origins of man was way off base and certainly not all that true. If people were religious, they might have felt offended by the secular explanation for the origins of man. A second group may have also agreed that man has evolved but would argued the post was incomplete and one sided. 

That basically leaves maybe a third of the class who might have felt the explanation for the origins of man had some merit. 

a.Reservations about Evolution in my Catholic Family

If the above description of our class is accurate, I must say I certainly understand that attitude and respect it. After all I was raised in a fairly pious Irish Catholic family who also rejected any notion of evolution. 

My uncle, for instance was a Catholic priest and my aunt was a nun in a covenant in San Francisco, My grandparents were especially pious and once my grandfather retired they would attend high mass every day and every evening they would say the rosary hour followed by listening to Bishop Fulton Sheen talk about living a good Catholic life.

I remember my grandparents were really skeptical of education in general and evolution in particular. When I said I wanted to go to college they insisted that if I had to go, I should at least attend a Catholic College like Saint May’s College or even better a Catholic college like Boston College or Notre Dame which catered to the children and grandchildren of Irish Immigrants.

While my uncle who was a priest was less hostile to academic ideas like evolution, he was a believer in Intelligent Design rather than Darwin’s notion of evolution.

Most of my relatives thought my interest in human origins was misspent. After 1974 when an American named Donald Johnson discovered the famous skeleton Lucy, Linda and I started taking our vacations in Africa to visit many of the famous dig sites. When we told our family about our trips, they thought we were wasting out time. Very few of my family members accepted the idea that we might have originated in Africa.

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                                                       Skepticism in Africa

Ironically as Linda and I acquired an interest in the origins of mankind, we were surprised to find that there were as many if not more skeptics of the idea of evolution in Africa than in the US. Admittedly our evidence was more anecdotal than scientific but we found the ambivalence among many Africans to be totally unexpected.

Maybe we should not have been so surprised. Given the poverty of most African nations, African nations initially showed little interest in the study human origins. The main impetus for the growth of human origins came from an Englishman named Louis Leakey who began the first major dig in the country of Tanzania. Today he is also famous for his many famous students such as Diana Fossey who studied the great apes and Jane Goodale who studied chimpanzees.

b. Foreign Studies of Human Origins

Because Leakey knew that humans shared 99% of their genes with chimpanzees and 98% with great apes, he wanted to study the three mammalian primates together to gain some idea of their common ancestors.

Because of Leakey’s success, by the 1980s there were numerous American paleontologists doing work in Africa. By the end of the decades just about every major American university had established a new department studying the nature of human origins.

c. Africans Take the Lead

By the time Linda and I started going to Africa, local Africans were beginning to play a bigger and bigger role in their country’s search for the origins of man. Many of these African paleontologists who had earned degrees from American universities, were instrumental in established research centers in their own country.

However, when we visited the main sites in Tanzania, Kenya and Ethiopia we found that many Africans were ambivalent about their country’s role in the new field of human evolution. While all of them showed great pride in the fact that their country and continent was maybe the birthplace of humanity, they were also troubled by the religious implications of the new findings.

d. Religious Reservations

Until we started spending time in Africa, I had not realized how religious many Africans are. While north Africa is overwhelming Muslim, west Africa has many countries with both Muslim and Christian populations. In contrast in East Africa the countries are overwhelming Christian, ranging from 85% of the population in Kenya to around 70% in Ethiopia.

The above significance became clear when we were in Kenya and our guide who was proud of Kenya’s contribution to human paleontology, asked me if I was a Christian. I remember I told him I was raised in a pious Catholic family. He then asked me how I resolved my Catholic faith with all of the new findings. I replied that I did not know how to resolve the two very different ideas. I just said that they were two alternative ways to view the world. 

The sentiment of our first guide was repeated during other trips to Africa. In Tanzania we had a wonderful agent who was very affable and helpful but he was very religious and troubled by the new findings.  He asked us to refrain from talking about evolution in his presence. Despite his aversion to the topic, he was very good at his job and during our stay at Leakey’s dig in Tanzania he got one of the workers to take us to the spot where Leaky had found Homo Habilis. If you remember an earlier post, humans first evolved from Lucy and her relatives around 2 million years ago. The very first of the 8 species of humans was Homo Habilis a find that made Leaky a star of the human paleontology world. 

While our guide took us to many great sites, the findings so upset his religious beliefs, that we had to limit our enthusiasm about visiting such great places. In various other casual conversation with residents in all the countries of east Africa, people keep voicing questions about their Christian faith and the new findings of paleontology.

e. The Threat of War

One top of these religious problems, we encountered yet another problem in Ethiopia and that was the start of a civil war in the country. Fortunately our guides had walkie talkies and they could tell if there was fighting going on in our future destinations. Our guides also managed to get us released from military stops where troops were looking for rebels.

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                                                Exploring the Options

When we finally stopped traveling to Africa, we had the feeling that the study of human origins was steadily growing in popularity while also stimulating pushback from an active religious community in Africa.

At that time I never realized how unpopular the idea of evolution was in the US. I might have also underestimated how many people might normatively reject its secular outlook of how human beings have evolved. When I finally got around to studying the polling data, I thought maybe I should just forget discussing human origins on the McClatchy website. 

However, I decided not to. Increasingly at American universities the study of human evolution has become an increasingly popular subject of study. The subject matter that is listed in the post is a subject that is increasingly taught every year at most American universities.

f. Answering Unanswered Questions

But I also thought that while there might be some people who have serious qualms about the doctrine, they might also be willing to see how theories of biological evolution explain 1) why animals appear the way they do, 2) how animals interact with one another, and 3) how they explain really difficult questions such as why humans became the smartest animal on the planet.

Even if people do not agree totally with the theory, some classmates might be surprised at how interesting are the insights that evolutionary biologists have developed over the past couple of decades. Modern evolutionary theory often offers explanations for human and animal traits that the other two theories are silent about.

I know that when Linda and I initially got interested in studying the topic in the early 80s, the findings were so fascinating that that we became hooked on the subject. Hopefully some of the evolutionary explanations may be equally intriguing and appealing to other members of our class. I am hoping that people’s sense of curiosity might overcome their reservations about the doctrine of evolution so that they would at least look at how evolutionary theory explains our dominant presence on this planet.

Diane Hinesley (Malone)

Bill Kelso

Dear Diane

Thanks for your nice letter. I know you like traveling and exploring new places. In case you are interested I thought I would tell you more about Africa, a fantastic place to visit.

                      Learning About Early Man: The Best Museums

If you are interested in the origins of man, there is no better place to see than Africa. However, conditions vary from one country to the next. Ethiopia has perhaps the best collection of ancient fossils as both the famous skeletons of Luci and now Ardi are in the National Museum of Ethiopia in Addas Ababa. 

Unfortunately because Ethiopia is a very poor country, its museum is rather threadbare. Hopefully some NGO or international group like the United Nations Heritage Fund will give them a grant to update their facilities.

Another country with a great program in human paleontology is Kenya. While Ethiopia is best known for early or proto man, Kenya is best known for later fossils from our genus Homo which eventually leads us to our species Homo Sapiens. Most of the fossils in Nairobi are thus post Lucy and consists of fossils from the human line such  as Homo Habilis or Homo Erectus. 

In addition Kenya is a much more prosperous nation than Ethiopia and has a first rate museum of human paleontology, perhaps the finest museum of human origins in the world. The country is also turning out a lot of very well educated young paleontologists who are becoming tourist guides.  Evidently you can make more money taking around wealthy Americans, Asians and Europeans than you can make by becoming a curator or college professor in Kenya. 

                           Armed Conflict and Rogue Soldiers and Cops

However, besides the quality of the museums and guides, you need to be aware of the political situation in each country. When we were in Ethiopia we got partly caught up in a very violent civil war. There are four main tribes in the country who seem to be constantly at odds. 

If you get stopped by troops, they can be pretty abusive. Because of the poverty of the nation, sometimes rogue policemen or soldiers will stop you and detain you in the hopes of securing a bribe. Fortunately, we had a wonderful guide who refused to be intimidate by anyone who also was very well spoken. He managed to get us out of several difficult situations because he was so persuasive. Because of his help, we managed to become good friends with hm and even sent him money as he struggled financially during the civil war in his country.

                                    Learning about Wildlife in Africa

Besides learning about early man, Africa is a great place to study animal behavior. At roughly the same time as proto man descended to the ground in east Africa, the large herds of zebra, wilderbeest and gazelle also emerged on the African savannah. In evolutionary terms, whenever there is a great die off or the environment is dramatically altered, mother nature quickly acts to fill the empty ecological niches. Besides creating numerous forms of herbivores, she also created numerous predators such as sabretooth tigers, lions, and hyenas and eventually humans

In a later post we shall see how these animals herds evolved to take advantage of the grassland on the African savannah while also defending themselves against their numerous predators.

In fact, for most of our early lives, humans were also prey or the hunted rather than predators or hunters. In the first several million years of our existence, humans had to struggle to survive. We shall see that what today we described as post-traumatic stress disorder may be part of an evolutionary adjustment humans acquired during our many years as rather helpless prey on the exposed grassland of Africa.

                                   Learning About the Slave Trade

Finally a fourth reason for visiting Africa is to see some of the after effects of the slave trade on select African tribes. While today there is much talk about slavery in America, we have to realize that Arabs were also major slave traffickers. While Europe and America got slaves from west Africa, Arabs got slaves from east Africa, If you hit the following link you will see that Ethiopia

                                 Map of Ethiopia next to Yemen and Saudi Arabia

is right next to Yemen and Saudi Arabia, two areas that constantly raided east Africa looking for young girls to be domestic slaves. 

                              Making their Women Unattractive as Domestic Slaves

To discourage slave traders from kidnapping their women, African tried to disfigure their women making them unattractive to Arab slave traders. To appreciate how dramatic was this change hit the link below about women with lip plates.

                                            African women with Lip Plates

Ironically while initially this practice was to make their women unappealing, with the passage of time, this alteration of women’s faces has become a source of attraction among females of some tribes. If you are in Ethiopia, you can visit some of these villages of remote tribes where the women have unusual looks.

However, I am ambivalent about this kind of sightseeing in Africa. If you go to these villages, the people are incredibly poor and will demand that you pay them to take their picture. But while they desire your money, they are understandably hostile to foreigners wanting to view them because of their unusual appearance.  In most of these village all of the men walk around carrying AK47s and they and their wives are often very inhospitable to foreigners.

After spending a little time in these villages, you feel like you are practicing the worst kind of voyeurism. After a while I felt that I as well as a few other stray visitors traveling in northern Ethiopia were not respecting a group of people who historically had suffered from the attacks of slave traders.

                                               An Unusual Continent

In this brief survey you can hopefully see what an interesting continent Africa is. Whether it is learning about early man, understanding how animals as well as humans learned to cope with predators or merely visualizing the long term impact of slavery on people, there is no other place in the world like Africa.

Bill Kelso

                                     Animals Who Love Music

Ever since I was a kid I loved music. But I never knew how many other people shared that interest. But the answer is probsbly quite a few. When I was in jr high and spend my weekends with my brother at Towers Records the place was always full of people.

In scanning the internet recently, I discovered that many animals also love music. Maybe they have more in common with humans than we realize. If you decide to watch the following link, be sure to watch the parrot who will end up doing a little dance to the music.   The picture of the elephant extending his trunk to the musicians is also priceless. It is also interesting that animals seem to like country music. This video probably makes people in Nashville very happy.

                                            Man sings to animals

Bill Kelso

                                           The Popularity of Music

I was able to find another video of animals who are music lovers. In the following clip a group of cows come running to hear a girl play an accordion, a woman singing and several guys playing the classic Dixieland song, “When the Saints Go Marching In,” a song made famous by Louie Armstrong in the 60s.

It is also interesting to learn that many animals have diverse musical interests as they seem to like listening to jazz as well as country music. 

                                                Animals who love Music

Diane Hinesley (Malone)

Diane Hinesley (Malone)

Bill Kelso

Dear Diane:

I am glad you and your friends had a nice trip to Africa. Also thanks for the tip about Carribean music. I was not familiar with their tradition of playing with steel drums at all.. The music sounds interesting. I will try to find more information about the subject on the internet.  Maybe with a little luck I can even find a video of Carribean musicians playing with steel drums. Again appreciate your information about music.

Take Care

Bill

Steven Lindfeldt (MidTerm)

 Bill,

Thanks for your research and your effort to make us all smarter humans at our advanced age. Maybe smarter than we deserve to be.  ( You know I have to put my reading glasses on to read this as I type.)  You spurred me to do a little reseach so I would have the names and dates correct for the story of my only close encounter with real anthropology. It was the spring of 1966.Still at UC Berkeley. A friend of mine,Rob, was dating Ann, the daughter of a famous anthropology professor. Ann had gone home for the weekend. That was all of about a mile from the south side of campus up Euclid Ave into the Berkeley hills on the nothside of campus. Rob had never been to the professor's home. He wanted to see the house and "hang" with the Prof. So I agreed to go with him. I guess I had nothing better to do. We are "hanging" at the house when a taxi pulls up out front. An elderly stately gentleman exists the cab and comes to the door. The Prof greets him warmly and escorts him into the house. The taxi driver is unloading a pile of luggage onto the sidewalk. The Prof looks at Rob and me and "got It".We went out to get the luggage and haul it in the house up the stairs to the guest bedroom. Amongst the luggage was a trunk. It was not heavy, but it was sealed very tightly. We came down stairs to see who was this person. It was Louis Leakey. Direct from Olduvai Gorge in East Africa. He was in the Bay Area to raise funds and lecture on his most recent discovery. The bones of the oldest human ever on earth whose bones were in the trunk we had carried to the guest bedroom. That was my first and only close encounter with real anthropology.

Bill Kelso

Dear Steve

I really enjoyed you letter about meeting Louis Leakey when you were at Berkeley. Until I read your letter I didn’t realize that he was giving lectures in America and raising money as early as the 1960s. I knew he had been profiled many times in Ameridan magazines, but I thought he primarily just stayed in Tanzania.

Given how expensive it was to undertake extensive digs in Africa I guess it makes sense he would raise funds in the US.

In any case, because of his extensive work in Africa, most people today would probably say that he is really the father of human paleontology and physical anthropology.

I remember reading a lot about his efforts to create the field of human paleontology. Prior to Leaky’s move to Africa in the early 1930s, most people in his home country of England had no idea about our human origins and showed little interest in the topic. While a few individuals were aware of the skeletons we today call Neanderthals, they had no idea of where we originated or how modern humans had developed. 

If people thought about evolution at all, they insisted that man must have originated in either Asia or Europe. Given the racial climate in the 30s and the discrimination against blacks, many Europeans insisted that if humans had evolved it must have occurred in Europe.

But Leakey strongly disagreed. Because he believed that humans as well as all the other primates had descended from a common ancestor, he insisted we human had evolved in Africa and not Europe. Despite a lot of criticism, he struck out on his own.

                      The Major Finds

At that time most anthropologists thought he was just an eccentric individual with some radical ideas. You have to admire him for his perseverence and his ability to ignore criticsm. However, after Leakey and his equally famous wife Mary moved to Africa, they started making many startling discoveries. The early criticism of Lakey soon gave way to  admiration for his major discoveries. Today the Leakeys are famous for three major finds.

a.Stone Tools

First they were the earliest paleontologists to find evidence that our ancestors started making stone tools around 2 million years ago. Since early humans did not become the dominant hunter in eastern Africa until about 70,000 years ago , early man used their stone tools to crack open the discarded bones from the kills of lions. Instead of being a hunter, early man was a scavenger, trying to find enough to eat from the left over remains of the top predators in east Africa. Since lions lacked the ability to crack open bones, our early ancestors could make a living by eating parts of the body that were hard for the major predators of east Africa to consume.

b. Early Human Fossils

The second major discovery of the Leakeys was the discovery of Homo Habilis, the skeleton of the very first species of our genus Homo. Homo Habilis who became known as “The Handy Man” was the first of 8 versions of early man that eventually lead to Homo Sapiens.

c. Early Footsteps

Finally the Leakeys gained a lot of press when Mary discovered the footprints made by early man, proving that at an early date man was bipedal. These early finds were widely published by the National Geographic and other science based journals.

                                            The  footsteps of early man

                                       The Americans Show up in Force

Because of the above finds, Leakey who had been a pioneer in looking for evidence of early man in Africa, was soon joined by a whole array of Americans who started their own digs in Africa.

 Since American universities were wealthier than comparable groups in England, numerous American colleges started major research efforts in east Africa.  The most famous of these American groups was led by Donald Johanson who discovered the skeleton of Lucy. Johanson and his team who loved rock and roll music, were playing the Beatles' song, “Lucy in the Sky with Diamonds” when they made their famous discovery, hence the name Lucy.

In light of the above success many American universities began to offer course in the origins of early man. The University of Arizona even created a well know research center which they asked Johanson to head.

                                             Changing African Tourism

Besides influencing the courses taught at American universities Leakey started to have an impact on African tourism. Right after WWII, when many African nation obtained their independence, they began to sponsor safaris in which tourists could watch the vast herds of animals that occupied the savannah of east Africa.  Because of Louis and Mary’s famous paleontological findings, several African nations found that many tourists also wanted to visit the famous dig sites in their country. It thus dawned on several African countries that they could combine people’s desire to learn more about their heritage with their interest in African wildlife.

While initially the study of early man and the safaris of east Africa seemed two unrelated events, they were in fact intimately linked. After all the origins of both early man and the rise of the animal herds on the African savanna were both caused by the same event.

The rift valley which had created a rain shadow on east Africa had dried out the previously existing African rain forest, creating in its place the semi arid savannah of east Africa. To fill this empty ecological niche, mother nature evolved modern man and a whole array of herbivores and predators. Whenever there are major disturbances in the environment, mother nature quickly acts to fill any ecological void.

Secondly, besides having the same cause, it was also clear that early man had made his living on the very plains that supported the herds of wildebeests, zebras and Thompson’s gazelles.

While today tourists can see millions of animals scattered on the horizon, they had to realize that for the previous 41/2 million years early humans had shared that savannah with similar animals. Humans along with zebra and wildebeest had faced the same problems in obtaining food and avoiding predators.  The interesting question was how defenseless and slow humans managed to survive this rather harsh environment.

Even more fundamentally Leakey’s created even more opportunities for people to learn about their ancestors. While today people can google Ancestors.com to find if their ancestors lived in England, or Germany or Asia or western Africa, today they can search further into their past. If they so choose, they can now go to east Africa and see where their earliest relatives happened to live.

So Steve, it must have been quite an occasions to meet Leakey. Very few people make a major change in the way people view the world. But Leakey not only altered what some American colleges teach, and how African tourism is structured, but he also changed the way we came to understand our human origins.

If Leakey had not defied conventional wisdom by moving to Africa to search for early man, we would probably still be in the dark about our early heritage. All in all, you had a unique experience with a very important individual.

Steven Lindfeldt (MidTerm)

Bill,

Thanks for the informative response to my attempt at a humoress story about my close enounter with real anthropology. I think what we are doing here is called "lifetime learning". On the other hand my recent contribution to lifetime learning was a comment I left on a video from a You Tube Vbloger where I explained the history of bubble gum in packs of baseball cards.  I don't remember Louis Leakey paying much attention to Rob and myself.

Bill Kelso

Dear Steve

Thanks for  your good natured and entertaining comments about Leakey. My comment was way too long and detailed.  I think it’s a defect I acquired from teaching so long.  A lighter touch is always desirable.

Bill